US846505A

US846505A - Gear-cutting machine.

Info

Publication number: US846505A
Application number: US23174804A
Authority: US
Inventors: John Parker
Original assignee: Brown and Sharpe Manufacturing Co
Current assignee: Brown and Sharpe Manufacturing Co
Priority date: 1904-11-07
Filing date: 1904-11-07
Publication date: 1907-03-12
Anticipated expiration: 1924-03-12

Description

No- 846,505. I PATENTED MAR. 12, 1907.

J. PARKER.

GEAR CUTTING MACHINE. APPLICATION FILED NOV. 1, i904.

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M Q G o o 44 49 5e 50 g g) fl I WITNESSES. F131. IINVENTDR'.

No- 846,505. PATENTED MAR. 12, 1907.

J. PARKER.

GEAR CUTTING MACHINE. APPLICATION FILED NOV. 7, 1904.

6 SHEETS-SHEET 2.

PATENTED MAR. 12, 1907.

J. PARKER. GEAR CUTTING MACHINE.

APPLICATION FILED NW. 7, 1904.

6 SHEETS-SHEET 3.

FE. I3.

INVENTCIR."

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., No. 846,505. PATENTED MAR. 12, 1907.

. J. PARKER.

GEAR CUTTING MACHINE.

APPLICATION FILED NOV. 7, 1904.

e SHEETS-SHBET 4.

E 79 E C) c WITNESSES; INVENTDRZ WITNESSEE'I.

J. PARKER. GEAR CUTTING MACHINE.

APPLICATION I'ILBD NOV. T, 190 4.

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PATENTED MAR. 12, v 1907.

6 SHEETS-SHEET 5.

W M I No. 846505. PATENTED MAR. 12, 1907.

J. PARKER. GEAR CUTTING MACHINE.

APPLICATION FILED NOV. 7, 1904.

6 SHEETS-SHEET B.

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UNITED sTATEs PATENT OFFICE.

JOHN P RKER, or PROVIDENCE, RHODE IsLAND, AssIeNo o BROWN AND SHARPE MANUFACTURING COMPANY, or PROVIDENCE, RHODE ISLAND,

ACORPORATIQN OF RHODE ISLAND.

GEAR-CUTTING MACHINE.

To all whom it may concern:

Be it known that I, JOHN PARKER, of the city and county of Providence and State of Rhode Island, have invented certain new and useful Improvements in Gear-Cutting Ma-' chines; and I do hereby declare the following specification, taken in connection with the accompanyin drawings, forming a part of the same, to e a full, clear, and exact description thereof.

The invention relates to that class of spur and bevel gear cutters in which the gearblank is supported upon a spindle which is indexed after each cut. to bring the blank into position for the cutting ofa new tooth and in which the cutting is performed by a rotary cutter mounted in a reciprocating cutter-carriage. machines of this type the cutter-carriage has been mounted u on a tilting bed, the angle of which could e varied to adapt the-machine for cutting-gears of different angles. This construction involved comparatively complicated driving and reversing mechanism and also limited the range of work for which the machines could be used. For instance, with this construction of machine the cutter could out only from the inside of the gear toward the outside, and the machine could not, therefore, be used to out many bevel gears having internal hubs. Neither could such machinesbe used to cut internal bevel-gears without the use of special attachments. I

In practicing the present invention the work-carrying spindle is mounted in a swivelhead which maybe adjusted to adapt the machine for cutting gears ofvaryingangle. By thusmounting the work-carrying spindle the range of work which may be done upon the machine is greatly increased as compared with the former construction of bevel and spur gear cutting machines. tion also enables the cutter-carriage to be mounted upon a fixed bed, with a resulting simplification of the driving and reversing mechanism which may be used for reciproeating the carriage.

- The-range of Work which may be done by I the machine is further increased by so constructing the work-carrying spindle that-the work may be supported at either end thereof,

or, in other words, by providing what may be Specification of Letters Patent. Applicationfiladlovombor 7, 1904- Berial Ho. 281,748.

Heretofore in gear-cutting This construeadjusted for gears of varying an le.

.Patented. March 12,1907.

termed a double-ended work-carrying s indlel" This form of spindle mounted in t e swivel-head also enables the use of a shorter bed for supporting and guiding the l cutter-carriage, with a resultin economy in space and inthe cost of man acturing the machine.

In practicing my invention I also provide the machine with a novel form of driving mechanism forthe cutter-spindle and also with a novel construction and arrangement of the gearing and connections for driving the various mechanisms of the machine.

I have also embodied in the machine various features of invention relating more or less to the construction of various parts and con- 'nections.

The various features of the invention'will be understood from the following detailed description of the machine in which I have embodied all such features in the forms in which I prefer to employ them.

This machine is shown in the accompanyingrdrawings, in which igure 1 is a rear side elevation of the ma- Fig. 2 is a front side elevation. Fig. 3 is an end elevation. Fig. 4 is a transverse sectional view on line 4 4, ig. '1. Fig. 5 is a sectional view on line 5 5, Fig. 4. Fig. 6 is a sectional view on line 6 6, Fig. 4. Fig. 7 is a horizontal sectional view on line 7 7, Fig. ,4. Fig. 8-is a partial end elevation of the left end of the machine, Fig. 2. Fig. 9 is a vertical sectional view on line 9 9, Fig. 2. Fig. 10 is a vertical sectional view on line 10 10, Fig. 3.

In the machine shown in the drawings the work is supported upon a spindle 1, mounted chine.

in a head 2, which is carried by a slide 3, vermay have a slight adjustment on the plate 7 for a purpose to be described. The plate 7 is provided with an annular flange 1 1, enga ing a cylindrical recess in the slide 3, whic forms a bearing in which the plate 7 and attached head 2 may be adjusted to vary the angle of the spindle 1. The head 2 and pla 7 thus form a swivel-head in which the spindle is carried, so'that the spindle may be swivel-head is held in any adjuste position The provide by means of bolts 12,provided -with heads throu h. an index worm-wheel 14, connected with t e spindle and engaged by a worm with a shaft 16, carried by the connected slide 3. The shaft 16 is mounted in a bushshaft 16. The vertica ing, 17 secured in the slide 3, and this bushing also carries a bearing 18, in which is mounted a bevel-gear 19, splined to a vertical shaft 20 and engaging a bevel-gear 21, secured to the shaft 20 is connected, by suitable gearing to be described, with the indexing mechanism. The shaft 16 1s concentrio with the axis about which the swivel-he ad 2 is adjustable, and the worm-wheel 14 therefore remains in engagement with the worm 1 5 in whatever position the spindle may be adjusted. The worm 15 is formed upon a sleeve 22, which has a bearing in a late 23, secured to the head 2 by abolt 24. n assembling the parts and bringing the worm-wheel into pro' er engagement with the worm 15 the hea 2 may be adjusted slightly on the plate 7, the bolt 24 being loosened, so that the plate 23 may assume the proper positlon with relation to the head. This adjustment is permitted by a sli ht clearance between the bolts 12 and the ho? which they pass and the clearance between the bolts 8 and the holes in the plate ,7 through which they pass. The adjustment of the head on the plate 7 may be effected by means'of a screw 25. The head may also be adjusted on the plate 7., as above indicated, to take up any wear between the worm and worm-wheel, and thus keep them in accurate relation. j

It is frequently desirable in setting up or adjustin the work to be able to turn the work in ependently of the indexing mechanism, and in order that this may be done without disconnecting the indexing-worm and worm-wheel the worm-wheel is so connected with the spindle that it may be readily disconnected or connected therewith at the will of the operator. For this purpose the wormwheel is secured upon a sleeve 26, surround ing the spindle and provided with a conical surface 27, engaging a similar surface on the spindle. When the sleeve 26 is forced forward, the conical or tapered surfaces are forced together, thereby connecting the spindle and worm-wheel. When the sleeve- 26 is released, the tapers are of such pitch that the sleeve automatically releases itself from the s indle, so that the spindle is f we to turn in t e sleeve. The sleeve 26 may be forced forward or released by means of a sleeve 28,-keyed to the spindle, but having a limited play thereon and arranged between the sleeve, 26 and a collar 29, which is engaged by the hub of a hand-wheel 30, threaded on es in the head 2 through supplorted the end of the spindle. By turning tne handheel the sleeve 28 may be forced forward, thus connecting the sleeve 26 with the spindle, or the pressure on the sleeve 28 may be released, thereby releasing the sleeve26, so that the spindle may be turned independently.

The spindle is provided with a tapered bearing 31, and in order that the wormwheel may be brought into accurate relation with the worm when the spindle is properly adjusted in its tapered bearin and when the tapers 27 on the sleeve 26 an spindle are in engagement the worm-wheel is connected with the sleeve 26 so that it may be adjusted longitudinally thereon. For thispurpose the worm-wheel is connected with the sleeve by a key and keyway and is held in position on the sleeve by means of adjusting-nuts 32. In order that the work way be adjusted with relation to the indexing mechanism in cutting opposite sides of the teeth or in making fine adujstments 0f the Work to bring it into proper relation With the cutter, means are provided for readily disconnecting and connecting the worm 15 with the shaft 16 and for turning the worm independently of the shaft to adjust the Work. For this purose the sleeve 22, on which the worm 15 is ormed, is providedwith a taper 33, arranged to engage a corresponding taper on the shaft 16. When these tapered surfaces are forced together, the worm and shaft are connected to rotate in unison, and when the pressure on the sleeve 22 is relieved the tapers are of such itch that the sleeve is automatically reeased and is free to rotate independent of the shaft. The sleeve 22 is forced forward to engage the tapers 33 by means of bolts 34, carried in a plate 35,held on the end of the shaft 16 by a nut 36. When the bolts 34 are loosened, the pressure on the sleeve 22 is relieved and the sleeve may be turned indeendently of the shaft 16 by means of the urled head 37, which extends beyond the plate 23, in which the sleeve is mounted. The swivel-head 2 is provided with a bearing 38 for supporting the arm 39, to which the outboard-bearing 40 may be secured.

The spindle is provided with a socket at each end for receivin a work-supporting arbor, so that the wor may be supported at either end of the spindle, according to the requirements of the particular piece of Work being operated upon. When the work is at the end of the spindle to which the and-wheel 30 is ap lied, this wheel may be removed, if found desirable, and a nut substituted therefor. By providing the spindle with means for supportingthe work at eitherend thereof pieces of work may be brought into proper relation with the cutter which could not be brought into such relation if the spindle were capa le of supporting the Work at only one IFO end.;'i..i iarious pieces of wdi'k may also by this construction be held in a more nearly uniform position with relation'to the travel of the cutter, so that the bed on which the cutter-carriage is mounted may be made shorter than would otherwise be practicable for the same ra e of work. The height of the spindle may adjusted by mo the slide 3 vertically on the ways 4, this a cfiustment being effected by means of a handwheel 41, secured upon a shaft which is cpnnected by bevel-gears 42 with adjusting de-' vices. (Not shown,)

The cutter-spindle 43 is carried by a cutter-carria e44, mounted to reciprocate on horizonta ways 45, formed on the bed of the machine. In order that the machine may be capable of performing a wide range of clamped ri idly work with a short travel of the cutter-carriage, the cutter-spindle is mounted in the head45, which may be adjusted longitudinally on the carriage to brin the cutter into proper relation with the wor This head is in adjusted position by means of be ts 46. v

The cutter-spindle is continuously driven durin the reciprocation of the cutter-carriage y meansof a chain or endless rack 47, provided with teeth which engage the teeth on a wheel or gear 48, securedto the cutterspindle. This endless rack or chain 47 passes over the wheel'48 and under two' idle pulle s 49, mounted on the cutter-head. From t e idle pulleys 49 the chain passes in op osite directions, the rear loop of the chain eing supported upon an idle pulley 50, carried by an arm 51 at the rear of the machine, and the front of the chain passin over a driving wheel or gear 52, Fig.4. This endless driving chain or rack forms a simple and efficient d-rlve for the cutter-spindle as. the cutterslide travels back and forth, and it also enables the cutter-head to be adjustably mounted on the cutter-slide without any complicato advance the cutter-carriage and is then rotated rapidly in the opposite direction to tion of the drivingmechanism for the spindle. It also enables the cutter-spindle to be longis tudinally adjusted without. involving any complications in the connections between the spindle and its driving mechamsm,s1nce the wheel 48 may move laterally with relation to the chain or rack 47 to accommodate such adjustment.

The cutter-carriage 44 is reciprocated through the rotation of a screw 53, which engages -a nut on the slide. (Not shown.) This screw is rotated slowly in one direction quickly return thecutter-carriage, the reversing of the screw being controlledby the movement of the cutter-carriage. A mech anism for reversing the movement of the cutter-carriage is shown in Figs. 1 and 7. The screw-shaft 53 is rotated in ,a direction to feed the cutter-carriage slowly forward by means of a worm-wheel 54, surrounding the shaft, and is rotated in a direction to quickly return the cutter caniage by means of a sprocket -wheel 55, also surrounding the s aft.. The shaft is connected with one or the other of these driving devices by means of a clutch 56, arranged between the hub of the worm-wheel and the hub of the sprocketwheel and provided with clutch-teeth arranged to engage clutch-teeth on said hubs, the clutch being 'splinedto the screw-shaft so as to rotate therewith, while being free to slide thereon.

The clutch 56 is shifted from one driving device to the other by means of a shifter-bar 57, on which are secured dogs 58, arranged in the path of a lug .59 on the cutter-carriage. When the cutter carriage reaches the end of its forward stroke, the lug 59 strikes one of the dogs,58, shifting the bar 57 forward. As the bar 57 moves forward a lug 6O thereon o crates upon the rear end of the clutchs ting lever 61 and swings the lever about its pivot. As the lever 61 is moved by the bar 57 a roll 62 on said lever acts on the V- shaped end of a spring-plunger 63, forcing sai plunger back until the roll passes the point of the V, when the plunger springs forward, thus shifting the clutch 56 quickly from engagement with the worm-wheel54 111130 engagement with the sprocket-wheel 55. The cutter-carriage is now uickly' returned until the lug 59 strikes the other dog 58, when the bar 57 is shifted in the opposite direction. In this movement of the bar a second lug 60 acts upon the clutch-shifting lever 61 to move it in the opposite direction, so that the clutch is shifted back into engagement with the worm-wheel 54.

As the bar 57 is shifted at the end of the return stroke of the cutter-carriage the indexing mechanism, which is located in the index-box 64, Fig. 1, is thrown into operation to index the work. This indexing mechanism is of a well-known form and is tripped by a dog carried by the collar 65, secured to the reversing-bar 57. The indexing mechanism is connected with the vertical shaft 20, through which the work-spindle is rotated by means of a shaft 66, connected by gearing67 with a shaft 68, carrying a bevelgear 69, which meshes with a bevel-gear 7 0 on said vertical shaft, Figs. 1 and 8. The indexing mechanism is operated from a constantly-rotating shaft 71.

The driving mechanism for driving the index-shaft 71 and the sprocket-wheel 55 for quickly returning the cutter-carriage at constant speeds and for driving the cutter-spindle and the" worm 54 for slowly feeding the cutter-carriage forward at any one of a number of different speeds is compactly and con veniently arranged in acasing at the end of the machine. These mechanisms are all driven from a driving-shaft 72, provided with a pulley 73, to which power may be applied. The index-shaft 71 and the sprocketwheel 55 for returning the cutter-carriage are driven from the shaft 72 through a spiral gear 73, which engages a spiral gear 74, secured to a shaft 75. This shaft 75 is provided with two sprocket-wheels 76 77, the s rocket-wheel 76 being connected with the s aft 71 by a s rocket-chain 78, which passes over the sproc et-wheel on the shaft 71, and the sprocket heel 77 being connected with the sprocketheel 55 by a sprocket-chain 7.9.

The worm-wheel 54 may be driven at any one of twelve different speeds by means of a variable-speed gearing interposed between the shaft 72 and said worm-wheel. This variable-speed gearing consists of an elongated pinion 80, formed on the shaft 72, which may be connected with any one of six gears 81 by means of an intermediate gear 82. The intermediate gear 82' is loosely mounted upon a shaft 83, carried by a frame 84, arranged to swing about the axis of the shaft 72. The intermediate gear 82 may be moved along the shaft 83 to bring it into position to engage any one of the gears 81 by means of a slide 85, provided with arms 86,

projecting on opposite sides of the gear. By moving the frame 84 about the axis of the shaft 72 the intermediate gear 82 may be brought into mesh with any one of the gears 81. The frame 84 is mounted upon one side upon the bushing 87, which forms one of the bearings for the shaft 72, and is secured on the other side to a sleeve 88, forming another bearing for the shaft 72 and extending outside of the casing. I The sleeve 88 is provided with an arm 89 outside the casing, by which the position of the sleeve 88 and the attached frame 87 may be varied. The arm 89 may be held in any one of the six positions corresponding to the positions of the intermediate gear 82 when in engagement with each of the six gears 81 by means of a pin 90, arranged to engage a series of holes 91in the casing, Big. 2.

. The slide 85, by which the gear 82 is adjusted along the rod 83, is guided in the recess in the front of the casing, being held in the I recess by a plate 92,1 igs. 3 and 5. The plate, and consequently the gear 82, may be held in any one of its adjusted positions by means of a sleeve 93, mounted upon a stud projecting from the slide 85 through a slot in the plate 92, the'platebeing provided with a series of recesses to receive the end of the sleeve 93. The gear 82 is adjusted. by withdrawing the sleeve 93 from a recess in the late 92, shifting the slide 85 laterally, and engaging the sleeve 93 with the proper recess.

Motion is transmitted from the gears 81 to the worm-wheel 54 through a shaft 94, which carries at its inner end a worm 95, engaging the worm-wheel, figs. 4 and 6. A quill-gear 96 is keyed to slide upon shaft 94 and is provided with a large gear arranged to engage the smaller of the two center gears 81 and with a small gear arranged to engage the largest gear 81. The quill-gear may be adjusted to bring either of its gears into engagement with the corresponding gear 81 by means of a shaft 97, provided at its inner end -with a inion 98, engaging annular teeth formed in the sleeve of the quillgear, and provided on its outer end with an operatingarm 99. The quill-gear is held in either one of its adjusted positions by means of a pin 100, carried by the arm 99 and arranged to engage either one of two holes 101 in the front of the casing. B this variable-speed gearing the worm-whee 54 may be driven at any one of twelve different speeds, and the change from one speed to another may be quickly and conveniently effected by the operator. The casing may be provided with proper scales to indicate the speed of the cut.- ter-carriage corresponding to the different adjustments of the slide 85 and the arm 99.

The cutter-spindle may be driven from the shaft 72. at any one of ten different speeds by means of a variable-speed gearing similar to the gearing already described for driving the worm-Wheel 54. This variable-speed mechanism connects the shaft 72 with a shaft 102,

u on which the gear or s rocket wheel 52, w ich carries the driving-c ain or rack 47, is

carried; Motion is transmitted from shaft 72 to shaft 102 through an elongated gear i which is connected, by-means of anintermediate gear corresponding to the gear 82, (shown in Fig. 5,) with any one of five gears 81 which in turn may be connected with the shaft102 by either one of the gears of a quillgear 96, he ed to slide on the shaft 102. The interme iate gear is adjusted by means of an arm 89, secured to the frame 84, which carries the intermediate gear of a slide corresponding to the slide. 85,-which is held in adjusted position by means of a sleeve 93, corresponding to the sleeve 93, already described. The quill-gear 96 is adjusted by means of a I shaft 97 provided with a pinion 98 and an operating-arm 99, similar tothe parts already described for adjusting the quill-gear 96.

This construction and arrangement of gearing for driving the various parts of the machine is simple in construction and compact in arrangement and is all located where it is readily and conveniently accessible to the operator in making any desired changes or adjustments.

What I claim, ters Patent, is

1. A machine for cutting bevel or spur gears having in combination a cutter-carriage, a reciprocating mechanism therefor, a cutter-spindle mounted on the carriage, mechanism for rotating the spindle during the reciprocation of the carriage, a workspindle, a swivel-head carrying said spindle,

and desire to secure by Letriage mounted to travel in a fixed path, re-

. as described.

T ew

head is mounted, and ind mechanism for the work-spindle, substantially. as de-.

scribed.

2. A machine for cutting bevel "or spur gears having in combination a cutter-carriage, a reciprocating mechanism therefpr, -a cutter-spin e mounted on the carriage, mechamsm for rotating the spindle d reciprocation of the carriage, a work-spindle, a swivel-head carrying said spindle adjustable about an axis spindle, a slide onwhich said head is .mounted adjustable at right angles to the movement of the cutter-carriage, and indexing mechanism for the cutter-spindle, substantially as described. a

3. A machine for cutting bevel or spur gears having in combination a cutter carriage, reciprocating mechanism therefor, a

cutter-spindle mounted on the carria e, a in which said spin e is workspindle, a head mounted adjustable to vary the inclination mechanism of the'work-slpindle, and inde for the wor -spindle, substantially as described.

4. A machine for cutting bevel or spur.

gears having in combination a cutter-carciprocating mechanism for the carriage, a cutter-spindle mounted on the carriage, a work-spmdle, a swivel-head carrying said s indle adjustable about an axis arallel to the axis of the cutter-spindle, an indexing mechanism for the work-spindle, substantially as described.

5. A machine for cutting bevel or spur gears having in combination a reciprocating cutter carriage, a rotary cutter spindle mounted thereon, a work-spindle provided with means for su porting the work at either end, a swivel-head carryin said spindle, and an adjustableslide on w 'ch the head is mounted, whereby either end of the spindle may be brou ht mto proper relation to act upon the wor carried thereby, substantially 6. A machine for cutting bevel or spur gears having in combination, a reciprocating cutter-carriage, a work spindle, a swivelhead carrying said spindle and means for supporting the work at either end of the spindle, whereby either end of the spindle may be brought into proper relation for the cutter to act upon the work carried thereby, substantially as described.

7. The combination with a reciprocating cutter-carriage, of a head adjustable longitudinally thereon, a cutter-spindle mounted in said head'and mechanism for rotating said spindle, substantially as described.

8. A gear-cutting machine having in combination, a main drivin -shaft, two conegears parallel to said sha t, adjustable intermediate gears' for connecting the cone-gears arallel to the ,cutter-- the main driving-shaft, a cutter-carriage, connections between one of said cona gears and the cutter-carriasame forward, and connections between the othercone-gear and the cutter-s indle for the spindle, substantiall; as describe I V 9. gear-cutting machine having in combination, a driving-shaft 72 provided'with two elongated gears, two cone gears corres onding to said elongated gears, an adjusta le intermediate gear for connecting each elongated gear with its cone-gear, a cuttercarnage, connections between one of said cone-gears and the carriage forfeedin'g the same forward, a cutter-spindle on the carriage, and connections between the other ge. for feeding the 4 coneear and the spindle for driving said spind e, substantially as described.

10. A machine for cutting bevel or spur gears, havin 1n combination a work-su porting spin le, a head in which said spin e 1s mounted, a drical bearing in which it may be adjusted, an index worm-wheel connected with the spindle, an index-worm mounted concentric with, the bearing of said plate, and means for eidjustably securm said head on said plate, substantially as. escribe a a 11. A machine for cutting .bevel or spur gears, havin in combination a work-su porting spin e, a head is mounted, a'.swivel-plate on which said head is adjustably justable slide carryin said plate, an index worm-wheelconnecte with the spindle, an index-worm.mounted concentric with the swivellate, and gearing connecting the work wlth the indexing mechanism, substantially as described.

12. A machine for cutting bevel or spur gears, havin in combination a work-su porting spin e, a head in which said spin e is mounted, a swivel-plate on which said head is adjustably secured,- an index wormwheel connected with the spindle, an indexworm mounted concentric with said swivelhead, a vertically-adjustable slide on which said plate is mounted, a vertical shaft. connected with the indexing mechanism, and gearing carried by said slide connecting said shaft with'said worm, substantially as described. I

13. Agear-cutting machine havingin combination, a work-supportin spindle, an index worm-wheel connecte therewith, an index-worm engaging said worm-wheel, a worm-shaft on whlch said worm is mounted, means for connecting and disconnecting the worm and worm-shaft, and means for tuming the worm manually independently of the worm-shaft, substantially as described.

14. A gear-cutting machine having in combination, a work-supportin spindle, an ininwhich said spin e plate providedwith a cylin- IIO dex worm-wheel connecte therewith, an 1 0 shaft, aclutch corresponding taper, a hea for forcing said sleeve forward to enga index-worm e aging said wheel, an indexshaft, and means for manually ,worm when disconnected from the shaft, substantiallyas described.

15. A gear-cutting machine having in combination, a Work-supporting spindle, an in- 1 dex worm wheel connected therewith, a worm-shaft provided with a taper, an indexworm mounted on said shaft and provided with a corresponding taper, means for forcing the worm independently of the shaft when the frictional engagement of the tapers is relieved, substantially as described.

16. A gear-cutting machine naving in combination, a work-supporting spindle, an inl dex-worm connected therewith, a wormshaft provided with a taper, a worm-sleeve mounted on said shaft and dprovided with a on said wormsleeve by which it may be turned, and means e t e tapers or relieving the pressure on the s eeve, suostantially as described.

17. A gear-cutting machine having in combination, a work-supporting sgiindle, an indeX worm-wheel connected t erewith, an index-worm engagin said wheel, and means for connecting and wheel with the spindle at will whereby the work-spindle may be turned independently or connecting said worm and necting the in turning the substantially as described.

' l bination,

ng said tapers together, and means for turni t e taper on the spindle, an

isconnecting the wormof the indeiiin mechanism without disconexing-worm and worm-wheel,

18. A gear-cutting machine having in coma work-supporting spindle, an index worm-wheel mounted thereon, a frictionclutch between the worm-wheel and spindle for connecting and disconnecting the same, and an index-worm engaging the wormwheel, substantially as described. 4

19. A gear-cutting machine having in combination, a work-supporting spindle provided with a taper, asleeve mounted thereon provided with a corresponding taper, an index worm-wheel on said sleeve, an indexworm engagin said worm-wheel, and means for forcing sai sleeve forward to engage'said tapers or relieving the pressure on said sleeve, substantially as described.

29. A gear-cutting machine having in combination, a work-supporting spindle rovid ed witha taper, a taper bearing in w ich said spindle is mounted, a sleeve mounted on said s indle provided with a ta er forengaging an index worm-- wheel adjustably mounted on said sleeve, substantially as described.

JOHN PARKER.

Witnesses:

W. H. THURsTon, J. H. THURSTON.